Adolescent coracoid morphology: a computed tomography morphometric analysis of growth across age groups

Coracoid transfer procedures, particularly the Latarjet, are increasingly employed to manage recurrent anterior shoulder instability in adolescents, given arthroscopic Bankart failure rates exceeding 40% in this young, active population. Despite this growing use, the morphologic characteristics of the adolescent coracoid remain poorly described. The purpose of this study was to describe the morphology and dimensions of the coracoid through adolescence to give insights and guidance for the planning of coracoid transfer procedures.

In this basic science morphometric study, 146 computed tomography scans from 11- to 17-year-old patients were included. Three-dimensional reconstructions were analyzed to obtain coracoid morphometric data, including length, width, and height at key anatomical landmarks. Morphological classification was conducted per established systems. Age-stratified analysis was performed. Interobserver reliability was assessed.

Mean coracoid length from tip to base was 41.5 mm (standard deviation [SD] = 4.6, confidence interval [CI]: 40.8-42.3). Mean length from tip to midsection and tip to elbow was 16.1 mm (SD = 3.1, CI: 15.6-16.6) and 25.4 mm (SD = 3.9 mm, CI: 24.8-26.1), respectively. Most dimensions significantly increased in size incrementally each year. Length of the coracoid in both coronal and axial views did not significantly increase between the ages of 11 and 13. By age 14, mean coracoid length was >40 mm and increased significantly with every subsequent year.

Adolescent coracoid morphology evolves with age. By mid-adolescence (14 years for both males and females), the adolescent coracoid has similar dimensions to that of the adult, suggesting it may support the feasibility of adult dual-fixation techniques in coracoid transfer procedures. Detailed pre-operative imaging and patient-specific planning remains essential to guide decision-making.